Puzzle of the week #94

Submitted by oldadmin on

Pawn promotion

Level
5-Queen
Chess Diagram
[Event "Puzzle #94"][Date "2009.11.06"][Result "1/2-1/2"][SetUp "1"][FEN "5Bk1/2R5/2p4P/p4p2/1p3P2/1P6/7p/1bK5 w - - 0 1"]
Pawn promotion is a very powerful and yet complicated moment in a game. A new piece is about to enter fresh in the game, changing the balance of forces forever. Of course stopping an opposite pawn from promoting drains your forces, so in general a weak player gives up when it cannot stop the pawn anymore. The above study was composed more than 100 years ago back in 1907. It is impressive how good the authors were in a time without chess books, or chess engines. Black is about to promote his pawn and apparently there's nothing White can do; the Black King stops White's passed pawn from promoting as well. Is White lost? Nothing is what it seems and chess is a game full of resources. Your tasks:
a) Analyse the position (10 points)
b) White to move and save a draw (10 points)

Total available points for this puzzle is 20. The answers will be published next week together with puzzle #95.

Puzzle #93 solution:
This puzzle was a study composed by S. Kaminer in 1935. It is not an easy one to solve, but I expected more students to at least give it a try at analysing the position and the obvious line starting with the obvious pawn promotion. Unfortunately I got only three correct answers, one being chosen as the most interesting one. Owen wrote:
a) Material position: Black has a better position than white because: 1. It has extra pawn. 2. It has two Bishops which are more powerful than two Knights in an open area (position).
King safety: 1. Black's King is very safe as a single Knight cannot checkmate it. Also it cannot do a perpetual check. There is no other piece next to it. The pawn on h7 looks like he is not a danger as the King and Bishops will defend the White pawn promoting into a Queen. 2. The White King is in trouble because Black's pair of Bishops can checkmate it. White's pawn on "a2" makes the White King's escape impossible.
Position: White looks like is losing the game and the only hope is promoting the passed pawn. Black has two Bishops which are a big advantage over the two White Knights and are about to check the White King and cause a lot of trouble. However White has the move which is its last hope. White cannot go ahead with the plan and promote the pawn
b) See solution:

[Event "Puzzle #93"][Date "2009.10.30"][Result "1-0"][SetUp "1"][FEN "8/2p2k1P/4p1N1/p5pb/7p/b7/P4P1P/1K4N1 w - - 0 1"]1.Nf4!! (1.h8=Q? Bxg6+ 2.Ka1 Be7! (2...Bf8? {This allows the White King and Queen to escape as follows} 3.Nf3 Bg7+ 4.Ne5+ Kf6 5.Qb8 Kxe5 6.Qb2+ Kf5 7.Qxg7 {White wins}) 3.Nf3 Bf6+ 4.Ne5+ Ke7 5.Qxf6+ (5.Qb8 Bxe5+ 6.Qb2 Bxb2+ 7.Kxb2 g4 {Black wins}) (5.Kb2 Bxh8 {Black wins}) 5...Kxf6 {Black wins}) 1...gxf4 2.h8=Q Bg6+ {Black is taking an advantage of the powerful Bishops} 3.Ka1 Be7 4.Nf3 Bf6+ 5.Ne5+ Ke7 6.Qxh4!! {Because the Black pawn took the White Knight on f4, now the pawn on h4 is not protected so White tries to escape by taking the Black pawn on h4. But the pawn is well defended by one Bishop; however suddenly the White Knight is becoming more powerful than two Bishops} 6...Bxh4 7.Nxg6+ Kf6 8.Nxh4 {White wins the game because of the material advantage}

Correct solutions:
Owen, Karl - 20 points
Andy Q - 19 points
Jeffrey - 10 points
Humphrey - 2 points

Standings:
Karl - 155 points
Owen - 137 points
Andy Q - 126 points
Rick - 115 points
Jeffrey - 85 points
Humphrey - 38 points
Nathaniel - 32 points
Alex - 25 points
James - 24 points
Katerina - 22 points
Wilson - 2 points